OBJECTIVETo determine the expressions of endothelial nitric oxide synthase traffic inducer (NOSTRIN) and endothelial nitric oxide synthase (eNOS) in the testis tissue of azoospermia patients, and investigate their correlation with the pathogenesis of azoospermia.

METHODSWe detected the expressions of NOSTRIN and NOSTRIN mRNA by immunohistochemistry and RT-PCR respectively, determined the activity of eNOS by spectrophotometry, and measured the stable metabolic end product NO, NO2- / NO3-, by nitrate reductase assay in the testis tissues of 17 patients with idiopathic azoospermia (the azoospermia group) and 10 normal men (the normal group).

RESULTSNOSTRIN and NOSTRIN mRNA were expressed in the spermatogonia, sertoli cells, stromal cells and vascular endothelial cells, more lowly in the azoospermia than in the normal group (0.312 +/- 0.076 versus 0.793 +/- 0.082, P < 0.01). The activity of eNOS was significantly increased in the idiopathic azoospermia patients ([33.727 +/- 3.58] U/mg) compared with the normal men ([17.69 +/- 3.84] U/mg) (P < 0.01). The level of NO2- / NO3- was significantly higher in the azoospermia than in the normal group ([48.56 +/- 8.49] micromol/L versus [25.37 +/- 9.61] micromol/L, P < 0.01). The expression of NOSTRIN showed a significant negative correlation with the activity of eNOS (r = -0.57, P < 0.01) as well as with the level of NO2- / NO3- (r = -0.61, P < 0.01) in the testis tissue of the idiopathic azoospermia patients.

CONCLUSIONThe expression of NOSTRIN is decreased, while the activity of eNOS and the level of NO2- / NO3- increased in the testis tissue of azoospermia patients, which may be associated with the pathogenesis of azoospermia.

Adult ; Azoospermia ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Male ; Nitrates ; analysis ; Nitric Oxide Synthase Type III ; metabolism ; Nitrites ; analysis ; Spermatogenesis ; Testis ; metabolism

AIMTo investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats.

METHODSThirty-two adult male Wistar rats were randomly divided into one sham-operated group (A) and three castrated groups (B, C and D). One week after surgery, rats were treated with normal saline (groups A and B) or oral icariin (1 mg/[kg.day] for group C and 5 mg/[kg.day] for group D) for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure (ICP) during electrostimulation of the cavernosal nerve. The serum testosterone (ST) levels, the percent of smooth muscle (PSM) in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and phosphodiesterase V (PDE5) in corpus cavernosum (CC) were also evaluated.

RESULTSICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A (P 0.01). However, ICP, PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B (P 0.05). Changes in ST and the expression of eNOS and PDE5 were not significant (P 0.05) in groups C and D compared with those in group B.

CONCLUSIONOral treatment with icariin ( 98.6 % purity) for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.

3',5'-Cyclic-GMP Phosphodiesterases ; genetics ; metabolism ; Animals ; Blood Pressure ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; Drugs, Chinese Herbal ; pharmacology ; Erectile Dysfunction ; drug therapy ; metabolism ; Flavonoids ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Male ; Muscle, Smooth ; drug effects ; physiology ; Nitric Oxide Synthase ; genetics ; metabolism ; Nitric Oxide Synthase Type I ; genetics ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Orchiectomy ; Penile Erection ; drug effects ; Penis ; drug effects ; enzymology ; Pressure ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Testosterone ; blood

OBJECTIVERecent studies suggest that the disruption of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) functions plays a pivotal role in the pathogenesis of bronchopulmonary dysplasia (BPD). The aim of this study was to investigate the changes of VEGF and eNOS expression in the lungs of premature rats exposed to moderate hyperoxia in order to explore possible relationships with BPD.

METHODSPremature rats delivered by hysterotomy at 21 days gestation were randomly continuously exposed to moderate hyperoxia (60% FiO2) and room air. The rats were sacrificed at 1, 4, 7, 11 and 14 days of exposure (6 rats at each time point). Lung sections were stained with hematoxylin and eosin for histological examination. Expression of VEGF and eNOS proteins and mRNA were assayed using immunohistochemistry and RT-PCR.

RESULTSAfter 4 days of hyperoxia, lungs developed interstitial fibrosis, abnormal vascular patterns and decreased alveolar septation. These changes became more obvious with more prolonged hyperoxia exposure. The expression of VEGF protein after 4 and 7 days of exposure decreased significantly in the hyperoxia group compared with controls. The expression of VEGF mRNA in the hyperoxia group was also lower after 4 and 7 days of exposure. Both VEGF protein and mRNA levels decreased with increasing hyperoxia exposure time. The expressions of eNOS protein and mRNA also progressively decreased with increasing hyperoxia exposure.

CONCLUSIONSHyperoxia caused progressive reduction in lung VEGF and eNOS expression as well as abnormalities of lung structures, including decreased vascular growth and impaired alveolarization. These histologic changes are similar to those of BPD. The data support a link between BPD and decreased expression of VEGF and eNOS.

Animals ; Bronchopulmonary Dysplasia ; etiology ; Female ; Humans ; Hyperoxia ; metabolism ; Infant, Newborn ; Lung ; metabolism ; pathology ; Male ; Nitric Oxide ; physiology ; Nitric Oxide Synthase Type III ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; genetics

BACKGROUNDStent thrombosis is one of severe complications after sirolimus-eluting stent implantation. Rapamycin (sirolimus) promotes arterial thrombosis in in vivo studies. However, the underlying molecular and transcriptional mechanisms of this adverse effect have not been thoroughly investigated. This study was designed to examine the effects of rapamycin on the expression of the gene, Kruppel-like factor 2 (KLF2), and its transcriptional targets in mice.

METHODSMice were randomly divided into four groups: the control group (intraperitoneal injection with 2.5% of dimethyl sulfoxide (DMSO) only), rapamycin group (intraperitoneal injection with 2 mg/kg of rapamycin only), Ad-LacZ + rapamycin group (carotid arterial incubation with Ad-LacZ plus intraperitoneal injection with 2 mg/kg of rapamycin 10 days later), and Ad-KLF2 + rapamycin group (carotid arterial incubation with Ad-KLF2 plus intraperitoneal injection with 2 mg/kg rapamycin 10 days later). The carotid arterial thrombosis formation was induced by FeCl3 and the time of arterial thrombosis was determined. Finally, the RNA and protein of carotid arteries were extracted for KLF2, tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1), endothelial nitric oxide synthase (eNOS), thrombomodulin (TM) mRNA and protein analysis.

RESULTSCompared with controls, treatment with rapamycin inhibited KLF2, eNOS and TM mRNA and protein expression, and enhanced TF and PAI-1 mRNA and protein expression, and shortened time to thrombotic occlusion from (1282 ± 347) seconds to (715 ± 120) seconds (P < 0.01) in vivo. Overexpression of KLF2 strongly reversed rapamycin-induced effects on KLF2, eNOS, TM, TF and PAI-1 expression. KLF2 overexpression increased the time to thrombotic occlusion to control levels in vivo.

CONCLUSIONSRapamycin induced an inhibition of KLF2 expression and an imbalance of anti- and pro-thrombotic gene expression, which promoted arterial thrombosis in vivo. Overexpression of KLF2 increased KLF2 expression and reversed time to thrombosis in vivo.

Animals ; Carotid Arteries ; metabolism ; Drug-Eluting Stents ; adverse effects ; Kruppel-Like Transcription Factors ; analysis ; genetics ; physiology ; Mice ; Mice, Inbred C57BL ; Nitric Oxide Synthase Type III ; physiology ; Plasminogen Activator Inhibitor 1 ; physiology ; Sirolimus ; pharmacology ; Thrombomodulin ; physiology ; Thrombosis ; chemically induced

OBJECTIVETo evaluate the effect of clearance of superoxide anion by catechin on the expression of nitrogen monoxidum (NO) and endothelial nitricoxide synthase (eNOS) and apoptosis in endothelial progenitor cells (EPCs) induced by angiotensin II (Ang II).

METHODSThe marrow endothelial progenitor cells of Sprague-Dawley rats were isolated and assigned to control (no treatment), Ang II treatment and Ang II + catechin treatment groups. After 48 hrs of culture, the concentration of O2*- in the supernate was measured by the NBT method, and NO concentration in the supernate was measured by the nitrate reductase method; the apoptosis rate of EPCs was detected by the TUNEL method; the mRNA expression of eNOS was detected by RT-PCR; the protein expression of eNOS was detected by Western blot analysis.

RESULTSAng II of 10-6 mol/L was determined as the suitable concentration for cell induction by the MTT test. Catechin of 400 mg/L was determined as an advisable intervention dosage. The apoptosis rate of EPCs in the control, the Ang II and the Ang II+catechin treatment groups were 2.48+/-0.12%, 54.18+/-0.77% and 16.87+/-0.35%, respectively, and there were significant differences among the three groups (P<0.01). The O2*- concentration in the Ang II and the Ang II+catechin treatment groups (81.7+/- 3.6 and 62.3+/- 2.2 U/L respectively) was significantly higher than that in the control group (33.7+/- 2.8 U/L) (P<0.01). An increased NO concentration was also found in the Ang II (189. 8+/- 9.0 micromol/L) and the Ang II+catechin treatment groups (276.4+/- 10.1 micromol/L) compared with that in the control group (105.8+/- 9.8 micromol/L) (P<0.01). There were significant differences in the concentrations of O2*- and NO between the Ang II and the Ang II+catechin treatment groups (P<0.05). The mRNA (P<0.05) and protein expression (P<0.01) of eNOS in the Ang II and the Ang II+catechin treatment groups increased significantly compared with those in the control group. The Ang II+catechin treatment group showed increased eNOS protein expression compared with the Ang II group (P<0.05).

CONCLUSIONSAng II may induce the generation of O2*-, inactivate NO and increase gene and protein expression of eNOS in EPCs. Catechin might decrease the apoptosis of EPCs through the effective clearance of O2*-and the reduction of NO inactivation and of eNOS protein uncoupling.

Angiotensin II ; pharmacology ; Animals ; Apoptosis ; drug effects ; Catechin ; pharmacology ; Cell Survival ; drug effects ; Endothelial Cells ; drug effects ; metabolism ; Female ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; drug effects ; metabolism ; Superoxides ; metabolism

BACKGROUNDCurrently, there are still divergent opinions about the mechanisms of the impaired neovascularization in diabetic subjects. Due to the remarkable therapeutic effect of angiotensin-converting enzyme inhibititors (ACEIs) on the reduction of blood pressure and the protection of target organs, the clinical application of this kind of drugs is very widespread. However, it is still not clear about the role and related molecular pathway of this kind of drugs in the limbs' postischemic revascularization. It is of major therapeutic importance to resolve these questions. This study aimed to investigate the reasons of the impaired angiogenesis in the hind limbs of rats with diabetic ischemia, the role and related molecular mechanisms of ACEI in postischemic revascularization.

METHODSHind limbs ischemia was induced in diabetic rats by right femoral artery excision. Diabetic rats were randomly allocated to one of the following treatments for 4 weeks: ACEI by perindopril; perindopril in combination with a nitric oxide synthase (NOS) inhibitor; perindopril in combination with bradykinin (BK)-B1 receptor (B1R) antagonist or saline. The differences of angiogenesis, the mRNA and protein expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and basic fibroblast (bFGF), constitutive nitric oxide synthase (cNOS) activity and nitric oxide (NO) content were observed after treatment.

RESULTSIn non-ischemic hind limbs, no significant changes in capillary density, or the mRNA and protein expression of eNOS, VEGF and bFGF, or the NO content and the cNOS activity were observed among all groups. On the contrary, in ischemic hind limbs, the capillary density in diabetic rats decreased by 27% when compared with the control rats, so did the mRNA and protein expression of eNOS, VEGF and bFGF, or the NO content and the cNOS activity (P < 0.05). The capillary density was increased by 1.65-fold in the perindopril treatment group in reference to untreated diabetic rats. Moreover, administration of perindopril enhanced the mRNA expression of eNOS, VEGF, and bFGF by 1.45-, 1.44-, and 1.33-fold, increased the protein content of the above indices by 1.55-, 1.30- and 1.50-fold compared with the untreated diabetic rats respectively. Perindopril also increased NO content and cNOS activity to 1.33- and 1.38-fold of that in untreated diabetic rats. The combination of BK-B1R antagonist significantly decreased the above indices (P < 0.05). In contrast, the combination of NOS inhibitor decreased the expression of eNOS and bFGF, the NO content and the cNOS activity, while the expression of VEGF did not change.

CONCLUSIONSDiabetes mellitus reduces the neovascularization, related growth factors expression and activity in the diabetic rat ischemic legs model. Treatment of perindopril improves postischemic revascularization. This effect is mediated, at least in part, by the BK-B1R-related pathway, and the activation of VEGF/eNOS/bFGF signals may be involved in the pro-angiogenic effect.

Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Blood Glucose ; analysis ; Diabetes Mellitus, Experimental ; physiopathology ; Extremities ; blood supply ; Fibroblast Growth Factor 2 ; genetics ; Neovascularization, Physiologic ; drug effects ; Nitric Oxide ; analysis ; Nitric Oxide Synthase Type III ; metabolism ; Perindopril ; pharmacology ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Streptozocin ; Vascular Endothelial Growth Factor A ; genetics

OBJECTIVETo explore the effects of glucose concentration fluctuation on function of cultured bovine arterial endothelial cells and underlying mechanism.

METHODSThe thoracic aorta of newborn calf was used for primary endothelial cells culture. Cells were divided into 3 groups and cultured for 48 h: control group (C, 5.5 mmol/L), constant high glucose group (HG, 30 mmol/L) and glucose fluctuation (GF, three circles of 2 h 30 mmol/L followed by 3 h 5.5 mmol/L, 30 mmol/L overnight, repeat the whole procedure on the following day) groups. The membranes fluidity of endothelial cells was detected by fluorescence polarization method. The contents of sorbierite, aldose reductase (AR), sorbitol dehydrogenase (SDH) and advanced glycation end products (AGEs) were measured. RAGE, eNOS and ET-1 mRNA expressions were detected by semi-quantitative RT-PCR.

RESULTSThe membranes fluidity of endothelial cells in HG or GF group were significantly decreased compared with the control group (all P < 0.01) and significantly lower in GF group than those in HG group (all P < 0.01). Sorbierite, AR and AGEs concentrations were significantly higher in HG and GF groups than those in control group (all P < 0.01) and AR and AGEs concentrations were significantly higher in GF group than that in HG group (all P < 0.01). SDH of endothelial cells in HG or GF group were decreased compared with the control group and lower in GF group than in HG group (all P < 0.05). In addition, the mRNA levels of RAGE, eNOS and ET-1 were significantly upregulated compared with the control group (all P < 0.01).

CONCLUSIONSGlucose concentration fluctuation can result in more severe bovine arterial endothelial cells dysfunction than high glucose via activating polyols metabolic pathways, upregulating the expression of AGEs, eNOS and ET-1. Therefore, glucose concentration fluctuation might play a crucial role on macrovascular complications of diabetes.

Aldehyde Reductase ; analysis ; Animals ; Aorta, Thoracic ; cytology ; Cattle ; Cells, Cultured ; Endothelial Cells ; metabolism ; pathology ; Endothelin-1 ; analysis ; Endothelium, Vascular ; cytology ; metabolism ; Glucose ; metabolism ; Glycation End Products, Advanced ; analysis ; L-Iditol 2-Dehydrogenase ; analysis ; Membrane Fluidity ; Nitric Oxide Synthase Type III ; analysis

Fluid shear stress plays a critical role in vascular health and disease. While protein kinase A (PKA) has been implicated in shear-stimulated signaling events in endothelial cells, it remains unclear whether and how PKA is stimulated in response to shear stress. This issue was addressed in the present study by monitoring the phosphorylation of endogenous substrates of PKA. Shear stress stimulated the phosphorylation of cAMP responsive element binding protein (CREB) in a PKA-dependent manner. Western blot analysis using the antibody reactive against the consensus motif of PKA substrates detected two proteins, P135 and P50, whose phosphorylation was increased by shear stress. The phosphorylation of P135 was blocked by a PKA inhibitor, H89, but not by a phosphoinositide 3-kinase inhibitor, wortmannin. Expression of a constitutively active PKA subunit stimulated P135 phosphorylation, supporting the potential of P135 as a PKA substrate. P135 was identified as endothelial nitric oxide synthase (eNOS) by immunoprecipitation study. PKA appeared to mediate shear stress-stimulated eNOS activation. Shear stress stimulated intracellular translocation of PKA activity from 'soluble' to 'particulate' fractions without involving cellular cAMP increase. Taken together, this study suggests that shear stress stimulates PKA-dependent phosphorylation of target proteins including eNOS, probably by enhancing intracellular site-specific interactions between protein kinase and substrates.
Animals ; Aorta, Thoracic/cytology ; Blotting, Western ; Cattle ; Cell Culture Techniques ; Cell Extracts ; Cells, Cultured ; Comparative Study ; Cyclic AMP-Dependent Protein Kinases/analysis/*metabolism ; Endothelium, Vascular/cytology/*enzymology/*metabolism ; Nitric Oxide Synthase Type III/analysis/*metabolism ; Phosphorylation ; Precipitin Tests ; Research Support, Non-U.S. Gov't ; Stress, Mechanical ; Time Factors

BACKGROUNDMetformin has become a cornerstone in the treatment of patients with type-2 diabetes. Accumulated evidence suggests that metformin supports direct cardiovascular effects. The present study aimed to investigate if metformin has beneficial effects on primary cardiomyocytes damaged by H2O2, and reveal the potential mechanism of action of metformin.

METHODSCardiomyocytes were incubated in the presence of 100 µmol/L H2O2 for 12 hours. Cardiomyocytes were pretreated with metformin at different concentrations and time and with aminoimidazole carboxamide ribonucleotide (AICAR) (500 µmol/L), an adenosine monophophate (AMP)-activated protein kinase (AMPK) agonist for 60 minutes before the addition of H2O2. Other cells were preincubated with compound C (an AMPK antagonist, 20 µmol/L) for 4 hours. The viability and apoptosis of cells were analyzed. AMPK, endothelial nitric oxide synthase (eNOS), and transforming growth factor (TGF)-β1 were analyzed using immunblotting.

RESULTSMetformin had antagonistic effects on the influences of H2O2 on cell viability and attenuated oxidative stress-induced apoptosis. Metformin also increased phosphorylation of AMPK and eNOS, and reduced the expression of TGF-β1, basic fibroblast growth factor (bFGF), and tumor necrosis factor (TNF)-α.

CONCLUSIONSMetformin has beneficial effects on cardiomyocytes, and this effect involves activation of the AMPK-eNOS pathway. Metformin may be potentially beneficial for the treatment of heart disease.

AMP-Activated Protein Kinases ; physiology ; Aminoimidazole Carboxamide ; analogs & derivatives ; pharmacology ; Animals ; Apoptosis ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Hypoglycemic Agents ; pharmacology ; Metformin ; pharmacology ; Myocytes, Cardiac ; drug effects ; metabolism ; Nitric Oxide Synthase Type III ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Ribonucleotides ; pharmacology ; Transforming Growth Factor beta1 ; genetics ; Tumor Necrosis Factor-alpha ; genetics